Good tool for copying directory tree, while excluding any duplicate files.

I've got a huge directory tree containing several directories that are near copies of each other. I'd like to perform a *non-destructive* copy of that directory to a new location, while ensuring that only unique files get copied. i.e. if the exact same file (byte-wise identical, excluding things like file-name, etc.) is in :

foo\bar\baz\a.jpgw\x\y\z.jpeg

Then i only want one of the files copied over (i don't care which one it is).

Can you copy one onto the other, skipping duplicates? It should be easy enough to do, I'd think. Otherwise, robocopy but I am on a tablet so playing with the switches would have to wait until later or someone else may beat me.

The next thing i'm looking for is a good 'similar photo' finder. Ideally it would find photos that are very close (including ones that are similar, once rotated 90/180/270 degrees). Anyone know of a particularly good app for this? There's lot of crap out there, and i wouldn't mind some good advice to cut through the chaff.